Sabine River, a river in Texas and Louisiana. It is 380 miles (612 km) long. The Sabine begins in northeastern Texas and flows southeastward to Logansport, Louisiana, where it turns southward. It flows into Toledo Bend Reservoir and continues along the Texas-Louisiana boundary. Near the Gulf of Mexico the river enters Sabine Lake, which drains into the gulf through Sabine Pass. The Sabine forms part of the Gulf Intracoastal Waterway and the Sabine-Neches Waterway, a channel that connects the Texas ports of Beaumont, Orange, and Port Arthur with the gulf.